As a fixing device for an image forming apparatus, there is a fixing device of induction heating type, whose heating roller contains an induction heating coil therein. Such a heating roller has a conductive roller of iron, and except for the edge portions, the outer surface of such a heating roller is coated with a releasing layer of a fluorine containing resin, such as Teflon (brand name), so as to prevent the adhesion of toner. The grounding of the heating roller has been performed as follows: the conductive roller is exposed at one edge of the heating roller so that a brush mounted on a grounded metal frame is allowed to contact the surface of the exposed edge of the conductive roller.
However, if the entire outer surface of the conductive roller is covered with a releasing layer, it is not possible to cause a sufficient antistatic effect on the conductive roller because the brush for eliminating electricity contacts the conductive roller via the releasing layer. In such a state, the conductive roller serves as an antenna for the induction heating coil, so that electric wave noises from the induction heating coil are emitted from the conductive roller.